Active matrix/organic light-emitting diode (AMOLED) display has currently become one of the hotspots in the research field of a flat-panel display. As compared with a liquid crystal display, the OLED has such advantages as low power consumption, low production cost, self luminescence, wide viewing angle and rapid response, so it has replaced the traditional liquid crystal display in display devices such as mobile phones, personal digital assistants (PDAs) and digital cameras. The design of a pixel driver circuit, as a core technology for the AMOLED display, is of very important significance.
Different from a thin film transistor (TFT)-LCD where a stable voltage is used to control the brightness, the OLED is driven by a current, so the stable current is required to control the light emission. Due to limitations of the manufacture process and the aging of elements, a threshold voltage (Vth) of a driving TFT for each pixel may be drifted, and the current flowing through the OLED of each pixel may be changed along with the threshold voltage. As a result, uneven display brightness will occur, and an image display effect will be adversely affected.
Because a fingerprint of each person is unique, it is able to remarkably improve the system security through a fingerprint identification technique, and this technique will fit well in security protection or high-end consumer electronic products.
Hence, how to integrate a touch in-cell technique and an AMOLED technique with the fingerprint identification technique will certainly be a new trend for the display technology.